1. Field of the Invention
This invention relates to systems, methods, and computer program products for monitoring networked devices. More particularly, to systems, methods, and computer program products for centrally monitoring devices connected to multiple networks while allowing for network address reuse among networks and network address-based monitoring within a network.
2. Discussion of the Background
Co-pending U.S. patent application Ser. No. 09/756,120 filed on Jan. 9, 2001, describes a system for remotely monitoring networked devices using e-mail. As described in that application, the Simple Network Management Protocol (SNMP) is used by a remote monitor to collect information from networked devices. The collected information is then sent to a central monitor using, for example, e-mail.
Devices connected to a network may be monitored by sending SNMP commands to the various devices based on their IP addresses. The devices will then respond to the SNMP queries with the requested information. The IP addresses of the devices are used to uniquely identify each device on a network. However, an IP address is not necessarily a globally-unique identifier for a particular device. For example, it is known to use network address translators (NAT) as an approach to reusing IP addresses on different networks. A NAT allows a network to have one or more globally-unique addresses by which they are known to the outside world (e.g., the Internet), without requiring that each node of the network behind the NAT have a globally unique IP address. This approach allows, for example, a company to reuse IP addresses on their different internal networks while still providing one or more globally-unique identifier(s) to the outside world.
These addressing complexities present difficulties to applications that wish to maintain information on the individual devices of a plurality of networks that may or may not share IP addresses. It would be desirable to have the ability to monitor network devices connected to multiple networks from a common central monitoring location. However, device address ambiguities increases the complexity of providing such a capability.